Commit b8fb5ab1 authored by Mark Brown's avatar Mark Brown
Browse files

regmap: Support raw reads from cached registers 



Fall back to a register by register read to do so; most likely we'll be
cache only so the overhead will be low.

Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent 7d5e525b

drivers/base/regmap/regmap.c

+22 −6
Original line number Diff line number Diff line
@@ -604,16 +604,32 @@ EXPORT_SYMBOL_GPL(regmap_read); 
int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,

		    size_t val_len)

{

	size_t val_count = val_len / map->format.val_bytes;

	int ret;



	WARN_ON(!regmap_volatile_range(map, reg, val_count) &&

		map->cache_type != REGCACHE_NONE);

	size_t val_bytes = map->format.val_bytes;

	size_t val_count = val_len / val_bytes;

	unsigned int v;

	int ret, i;



	mutex_lock(&map->lock);



	if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||

	    map->cache_type == REGCACHE_NONE) {

		/* Physical block read if there's no cache involved */

		ret = _regmap_raw_read(map, reg, val, val_len);



	} else {

		/* Otherwise go word by word for the cache; should be low

		 * cost as we expect to hit the cache.

		 */

		for (i = 0; i < val_count; i++) {

			ret = _regmap_read(map, reg + i, &v);

			if (ret != 0)

				goto out;



			map->format.format_val(val + (i * val_bytes), v);

		}

	}



 out:

	mutex_unlock(&map->lock);



	return ret;